Make bin/replQ work work with non-bootstrapped compilation

bin/scalaQ

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" >& /dev/null && pwd)/.."
+. $ROOT/bin/commonQ
+
+# Runs a class compiled with bin/scalacQ on the classpath written by `sbt buildQuick`
+# (compiler + freshly built stdlib).
+#
+#   bin/scalacQ -d out MyFile.scala
+#   bin/scalaQ -cp out MyMain arg1
+#
+# Without -cp, classes are looked up in the current directory.
+
+extraCp="."
+if [ "$1" = "-cp" ] || [ "$1" = "-classpath" ]; then
+  extraCp="$2"
+  shift 2
+fi
+
+java -cp "$extraCp:$cp" "$@"

build.sbt

@@ -9,6 +9,7 @@ val `scala3-compiler-nonbootstrapped` = Build.`scala3-compiler-nonbootstrapped`
 val `scala3-compiler-bootstrapped` = Build.`scala3-compiler-bootstrapped`
 
 val `scala3-repl` = Build.`scala3-repl`
+val `scala3-repl-nonbootstrapped` = Build.`scala3-repl-nonbootstrapped`
 
 // The Standard Library
 val `scala2-library` = Build.`scala2-library`

project/Build.scala

@@ -51,7 +51,7 @@ object Build {
   // Used to run binaries similar to ./bin/scala script
   val scala = inputKey[Unit]("run compiled binary using the correct classpath, or the user supplied classpath")
 
-  val buildQuick = taskKey[Unit]("compile the compiler and REPL, write classpath to bin/.cp for use by bin/scalacQ and bin/replQ")
+  val buildQuick = taskKey[Unit]("compile the compiler and REPL, write classpath to bin/.cp for use by bin/scalacQ, bin/scalaQ and bin/replQ")
 
   // Settings used to configure the test language server
   val ideTestsCompilerVersion = taskKey[String]("Compiler version to use in IDE tests")
@@ -609,6 +609,7 @@ object Build {
     `scala3-staging`,
     `scala3-tasty-inspector`,
     `scala3-repl`,
+    `scala3-repl-nonbootstrapped`,
     `scala2-library`,
     scaladoc,
     `scaladoc-testcases`,
@@ -636,7 +637,8 @@ object Build {
 
   lazy val `scala3-nonbootstrapped` = project.in(file("."))
     .aggregate(`scala3-interfaces`, `scala3-library-nonbootstrapped` , `scala-library-nonbootstrapped`,
-      `tasty-core-nonbootstrapped`, `scala3-directives-parser-nonbootstrapped`, `scala3-compiler-nonbootstrapped`, `scala3-sbt-bridge-nonbootstrapped`)
+      `tasty-core-nonbootstrapped`, `scala3-directives-parser-nonbootstrapped`, `scala3-compiler-nonbootstrapped`,
+      `scala3-sbt-bridge-nonbootstrapped`, `scala3-repl-nonbootstrapped`)
     .settings(
       name          := "scala3-nonbootstrapped",
       moduleName    := "scala3-nonbootstrapped",
@@ -666,13 +668,11 @@ object Build {
         libraryProject = `scala-library-nonbootstrapped`,
         withCompilerDeps = withCompilerClasspath(`scala3-compiler-nonbootstrapped`)
       ).evaluated,
-      // TODO: scala3-repl depends on the bootstrapped compiler, making this slower
-      // than it needs to be. A non-bootstrapped REPL project would speed this up.
       buildQuick := {
-        val _ = (`scala3-repl` / Compile / compile).value
-        val cp = (`scala3-repl` / Compile / fullClasspath).value.map(_.data.getAbsolutePath).mkString(File.pathSeparator)
+        val _ = (`scala3-repl-nonbootstrapped` / Compile / compile).value
+        val cp = (`scala3-repl-nonbootstrapped` / Compile / fullClasspath).value.map(_.data.getAbsolutePath).mkString(File.pathSeparator)
         IO.write(baseDirectory.value / "bin" / ".cp", cp)
-        streams.value.log.info(s"Wrote classpath to bin/.cp — use bin/scalacQ and bin/replQ")
+        streams.value.log.info(s"Wrote classpath to bin/.cp — use bin/scalacQ, bin/scalaQ and bin/replQ")
       },
       testCompilation := testCompilationTask(
         compilerProject = `scala3-compiler-nonbootstrapped`,
@@ -852,7 +852,6 @@ object Build {
       bspEnabled := false,
     )
 
-  /* Configuration of the org.scala-lang:scala3-tasty-inspector:*.**.**-bootstrapped project */
   lazy val `scala3-tasty-inspector` = project.in(file("tasty-inspector"))
     // We want the compiler to be present in the compiler classpath when compiling this project but not
     // when compiling a project that depends on scala3-tasty-inspector (see sbt-test/sbt-dotty/tasty-inspector-example-project),
@@ -883,52 +882,74 @@ object Build {
       bspEnabled := false,
     )
 
+  /* Settings shared between the `scala3-repl` and `scala3-repl-nonbootstrapped` projects */
+  lazy val replSettings = Def.settings(
+    moduleName    := "scala3-repl",
+    versionScheme := Some("semver-spec"),
+    crossPaths    := true,
+    // sbt shouldn't add the stdlib automatically, we depend on it transitively via the compiler project
+    autoScalaLibrary := false,
+    // Add the source directories of the REPL
+    Compile / unmanagedSourceDirectories   := Seq(baseDirectory.value / "src"),
+    Compile / unmanagedResourceDirectories := Seq(baseDirectory.value / "resources"),
+    Test    / unmanagedSourceDirectories   := Seq(baseDirectory.value / "test"),
+    Test    / unmanagedResourceDirectories := Seq(baseDirectory.value / "test-resources"),
+    // All the dependencies needed by the REPL
+    libraryDependencies ++= Seq(
+      Dependencies.jlineReader,
+      Dependencies.jlineTerminal,
+      Dependencies.jlineTerminalJni,
+      Dependencies.sbtJunitInterface % Test,
+      Dependencies.coursierInterface, // used by the REPL for dependency resolution
+    ),
+    run / fork := true,
+    Compile / run := {
+      //val classpath = s"-classpath ${(`scala-library-bootstrapped` / Compile / packageBin).value}"
+      // TODO: We should use the val above instead of `-usejavacp` below. SBT crashes we we have a val and we call toTask
+      // with it as a parameter. THIS IS NOT A LEGIT USE CASE OF THE `-usejavacp` FLAG.
+      (Compile / run).partialInput(" -usejavacp").evaluated
+    },
+  )
+
   lazy val `scala3-repl` = project.in(file("repl"))
     .dependsOn(`scala3-compiler-bootstrapped` % "compile->compile;test->test", `scala3-directives-parser-bootstrapped`)
     .settings(publishSettings)
+    .settings(replSettings)
     .settings(
       name          := "scala3-repl",
-      moduleName    := "scala3-repl",
       version       := dottyVersion,
-      versionScheme := Some("semver-spec"),
       scalaVersion  := dottyNonBootstrappedVersion,
-      crossPaths    := true,
-      autoScalaLibrary := false,
-      // Add the source directories for the sbt-bridge (bootstrapped)
-      Compile / unmanagedSourceDirectories   := Seq(baseDirectory.value / "src"),
-      Compile / unmanagedResourceDirectories := Seq(baseDirectory.value / "resources"),
-      Test    / unmanagedSourceDirectories   := Seq(baseDirectory.value / "test"),
-      Test    / unmanagedResourceDirectories := Seq(baseDirectory.value / "test-resources"),
-      // Packaging configuration of `scala3-staging`
+      // Packaging configuration of `scala3-repl`
       Compile / packageBin / publishArtifact := true,
       Compile / packageDoc / publishArtifact := true,
       Compile / packageSrc / publishArtifact := true,
       // Only publish compilation artifacts, no test artifacts
       Test    / publishArtifact := false,
       publish / skip := false,
-      libraryDependencies ++= Seq(
-        Dependencies.jlineReader,
-        Dependencies.jlineTerminal,
-        Dependencies.jlineTerminalJni,
-        Dependencies.sbtJunitInterface % Test,
-        Dependencies.coursierInterface, // used by the REPL for dependency resolution
-      ),
       // Configure to use the non-bootstrapped compiler
       bootstrappedScalaInstanceSettings,
       // Needed for the JSR223 tests which are "run" tests
       Test / javaOptions += s"-Ddotty.tests.classes.scalaLibrary=${(`scala-library-bootstrapped` / Compile / packageBin).value}",
-      run / fork := true,
       excludeDependencies += "org.scala-lang" %% "scala3-library",
       excludeDependencies += "org.scala-lang" % "scala-library",
-      Compile / run := {
-        //val classpath = s"-classpath ${(`scala-library-bootstrapped` / Compile / packageBin).value}"
-        // TODO: We should use the val above instead of `-usejavacp` below. SBT crashes we we have a val and we call toTask
-        // with it as a parameter. THIS IS NOT A LEGIT USE CASE OF THE `-usejavacp` FLAG.
-        (Compile / run).partialInput(" -usejavacp").evaluated
-      },
       bspEnabled := enableBspAllProjects,
     )
 
+  lazy val `scala3-repl-nonbootstrapped` = project.in(file("repl"))
+    .dependsOn(`scala3-compiler-nonbootstrapped` % "compile->compile;test->test", `scala3-directives-parser-nonbootstrapped`)
+    .settings(replSettings)
+    .settings(
+      name          := "scala3-repl-nonbootstrapped",
+      version       := dottyNonBootstrappedVersion,
+      scalaVersion  := referenceVersion,
+      Compile / mainClass := Some("dotty.tools.repl.Main"),
+      publish / skip := true,
+      target := target.value / "scala3-repl-nonbootstrapped",
+      fetchedScalaInstanceSettings,
+      Test / javaOptions += s"-Ddotty.tests.classes.scalaLibrary=${(`scala-library-nonbootstrapped` / Compile / packageBin).value}",
+      bspEnabled := true,
+    )
+
   // ==============================================================================================
   // =================================== SCALA STANDARD LIBRARY ===================================
   // ==============================================================================================